This invention relates to displays or signs wherein indicia such as prices of items in a store or on a menu are presented for observation. More specifically, the invention is concerned with improvements in the type of display wherein numerals or letters of the alphabet are fixed on a precoiled plastic tape.
A display device using tape is exemplified in U.S. Pat. No. 3,939,584, dated Feb. 24, 1976, and assigned to the assignee of this application. The embodiment shown in FIG. 9 of the cited patent is typical of the kind of display device to which the present improvements apply.
In display devices wherein information to be displayed is represented by translucent areas bounded by opaque areas on a tape, the tape is translated over a convex translucent surface such that the rear side of the tape may be, but does not necessarily have to be, exposed to a light source and the front side of the tape may be exposed for observation. The tape is prestressed or precoiled so it desirably has a tendency to wind itself into a coil if left unrestrained. By proper guidance, the tape may be caused to follow a path before and after it passes over the translucent surface which permits opposite ends of the tape to coil. In prior display devices of the type here under consideration and in the improved device, the tape is translated to present consecutive indicia by applying pressure with the fingers and simultaneously exerting a translational force on the front surface of the tape. However, since the opposite end portions of the tape which are coiling and uncoiling, respectively, are not usually visible to the operator, there are occasions when translating or winding of the tape is carried on to the extent that one uncoiling end of the tape is set free. This results in a single coil being formed and requires that the leading end of the tape be rethreaded into the holder which is a time consuming operation.